Calling mechanism for party-line exchanges.



. 12,5. ANliE-RSON.

'CALLING MECHANISMFOR PARTY LINE EXCHANGES. Arman" nun 1.20. \bln lgurwz'n an. 21'. 1011.

1,248,782; 4 Patmbd 1m. 4-. 1911.

I IIIIITHNEET I.

ll" m C. A. ANDERSON. cnum; MECHANISM FOR umv'uus Pitented-Dee. 4,1917.

I SNEETQ-SNIET 3 EXCHANGES. APPLICATION FILED Ill. 20. "H- REIIEWED APR- 2h III! c. A;. ANDERSON CALLING MECHANISM FOR PARTY L INE EXCHANGES.

APPLICATION man mm 20 1911 BENHIED APR 2| m1 7 Patented Dec, 4,1917.

v I {SHEETS-SHEET 5 E97.

I C. A. ANDERSON. CALLING MECHANISM FOR PAR Armcrnou FILED mm. 20. NH.

TY LINE EXCHANGES.

RENEWED APR. 21. I911- Patented Dec. 4,1917. 1 suns-sum s GES.

Patented-Dec. 4, 1917.

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CALLING MECHANISM FOR PARTY-LINE EXGHANGES.

Specification of Letters Patent.

Patented Dec. 4, 191a.

Application-filed March 20, 1911, Serial No. 615,470. Benewed April 21, 1917. serial NoQIB SJO'I,

To all whom it may concern.-

Be it known that I, CLARENCE A. ANDER- soN, a citizen of the United States. of America, and a resident of Chicago,"county of Cook, and State of Illinois, have invented certain new and useful Improvements in Calling Mechanisms for Party-Line Exchanges, of which the following is a specifi cation.

My invention relates to calling mechanism for party line exchanges and has for its object improvements in such mechanism for the purpose of facilitating the operations by and under the control of the central oilice operator.

In the accompanying drawings Figure l is an elevation of t e impulse sending apparatus;

Fig. 2 is a plan of the same;

Figs. 3, 4 and 5 are enlarged sectional elevations on line 33, 44 and 55, respectivey, of Fig. 2;

6 is an enlarged elevation of the switc ling relay and contact springs;

Fig. 7 is a plan of the key board by means of which the operator determines what sta tions shall be telephonically connected to the party line; I

Fig. 8 is a side elevation of Fig. 7;

Fig. 9 is an elevation of the right end of Fig. 8;

Fig. 10 is a sectional elevation corresponding to Fig. 9;

Fig. 11 is a section on Fig. 8;

Fig. 12 is a diagram of the circuits involved; and

Fig. 13 is a detail of the magnet and devices used for controlling the supervisory lamp.

The impulse sending apparatus is mounted upon a bed plate shown broken away in Fig. 2. A motor M (Fig. 12) is used to drive the apparatus as will be hereinafter lines ll11 of described. The motor shaft M (Figs. 2

and 3) has a Worm M on its-end which en-' gages and turns a gear M on the shaft M}. On the other end of thesha ft Mt is asleeve which is moved longitudinally on the-shaft by a clutch magnet A. This sleeve has a. disk which is adjacent to another disk-on a shaft supported in a bearing M The two disks when in engagement with each other by the action ofthe magnet A forma friction clut h M and the engagementv of the clutch ca ses a driving of the pinion M" on the other end of the shaft suppdrted in bear-' 111g Through earing, as sh wn n ig.- 4l, 'the driving of the pinion M serves to drive the gear N in the direction shown by the arrow. 1

The'gear N is loosely mounted on Shaft N and is provided with a pawl N? a(lg'tp teg'l to engage and drive a ratchet wheel N fast? to said shaft N A clock spring N 2) normally holds the ratchet wheel N Wi a pm N 5 against a sto' N. The construe tion of the parts so ar described is such that when the clutch magnet A is energized the clutch M will be thrown into operation and the motor M, operating "throu h the. parts described, will drive the shaft and consequently anything secured thereto, in the direction shown by the arrow of Fig. When the clutch M is released by the dean;

ergization of the magnet A, the spring N} v will return the shaft'N -h and parts carried thereby, to normal position with pin N against stop N 1 r Secured to the shaft N is a wheel TP hav ng notches P adapted, when the wheel P is moved, to engage a pin P mounted one contact spring 36. Secured on the wheel P is a pin P (shown in section in Fig. which normally rests between an arm P,

loosely supported on the shaft N and a.

projection on arm P pivoted on the adjacent frame. In the normal position of the wheel P, the pin P holds the arm P in an elevated position so that a. pin P acts to shift contact SPIl as shownin Fig. 5. When the wheel P 1s advanced by reason of operation of the clutch Mflthe pin? forces the arm P downward, and as the outer end of the arm I is over the pin Tithe aid pin P is moved so as to permit the adjacent contact springs to assume an auemawpssi. tion, which alternate position is that "(1116. to their initial tension. I

Pivotally' su orted on the wheel P are contact makers i to engage insulated contact pins R and 5, respectively, supported in quadrants on suitable brackets as shown in Figs. .1, 3 and .5. These parts are so arrangedfthat the conl; tact makers Rand S will engagethei 1TB: spective contact pins and S alternate]. 1 when the Wheel P is advanced as the,resat of closing the clutch M. .Ilhe particular operations involved will beegme moreagpf Parent by aeo sid a en. f t e ensue hereinafter to be described.

Supported at any convenient place, as on shall be moved,

"The key board consists of a frame, 'a series ofkeys, a magnet, and contact springs cohtrolling the magnet. The frame consists (as. tbpplate T, to which is secured a web (Phterminatingf in a chamber T in which ehamber there is a magnet B which extends nearly the entire length of tl1e frame. Arra'ngedto slide and be guided in the top T and the, expanded part of T which forms the chamber T are a series of keys V pro vided with cones V on their stems, and heads V in the chamber T 'and directly over the magnet B. These keys are normalIysu pQrted in an elevated pos1t1on by springs V? asshown in Fig. 10. Pivoted to thejrame'arebails B and B which sur d the'magnet B and are in the paths of the wadsV fof the keys V so that when one of" those keys'is depressed the head V there onstrikes a bail, B or B and turns it on its pivot. In so moving a hail, the depressed head V comes close to the pole of the magnan so thatit a current is flowing'through the magnet B at the time, the said magnet will act upon the depressed head V as upon an ai'mature to hold the key in its depressed position. In their normally elevated os1- tion, however, the heads V are so far a ove the magnetBthat said magnet does not have owersuflicient to attract them against the orceof their elevating springs V :"O Ii the bails B and B are arms B and B (Figs. land 11) w'ith'pieces of insulation at their upperends adapted to engage close adjacent contact springs when one attire bails is depressed. These cont-act springs control a circuit through the magnet B,,a d"the. springs on one side are mere d 'plicatesof those'on the other. The consequence is. that, when one of the keys V 1s depressedaibai'lflB or, B is also depressed and'a cir'cuiths' closed for the magnet B, and saidmagn'et, acting upon its temporary arinature'W, holds itsown circuit closed uhtil-itiisbroken by other means as will be hereinafterjse't forth.

:YAdjafcenfto each key V is a series of contact sprin'gs which makeione series of connecae s when III'IOIIB positlon and d fierent connections when the are shifted. The mechanicalbperation o-shifting these springs is are-(saga the cone V on the stem of the key V, and will be clearly apparent from an inspection of Figs. 9 and 10 without special other indicating mark, representing the station on a party line which has a similar number. Thus, the key V having 1 beside it is used in calling station No.1, the key having 5 is used in calling station No. 5, and so on. One of the keys marked R in Fig. 7, is a release key and not used for any station. Another key without a mark is functionless, as far as the present application is concerned, but is pro-- vided as part of the general equipment to be properly connected and used when one keyboard is provided for two operators positions and is to be used byboth operators.

There are provided an operators telephone set, cord circuits, plugs, jacks, ringing' and listening keys, and other devices ordinarily used in a central oflice. Of these there are shown in the diagram one ack from which a party line extends, a plug and part of one cord circuit, and a ringing key K shown in dotted lines. There are also shown an ordinary drop below the jack and a visual signal above. There is one of each of these for each party line. Connected with the party line there is shown one local station with the circuits shown with a comparative degree of fullness for the purpose of illustrating the type of local station with which the calling mechanism is usually associated and to which it is well adapted. As the present invention relates to the central ofiice apparatus and not to that of the local stations, and as the type of local station will be recognized by those skilled in the art, the local circuits will not be given in detail.

The visual signal apparatus, however, forms an lmportant part of the central office apparatus and will be described in enough detail to illustrate its action. It consists of a polarized magnet-L and armature of the same kind as those used for stepping magnets at the local stations, and this which tends to remain in theposition to which it is thrown by the magnet. Fig. 13 shows L in the position which it occupies when a stepping impulse has last been sent over the line. In this position L is in en-' gagement with a contact L, which in turn I and 9:

is electricallyconnected with L. When another stepping impulse iiows through L- the pin on the lower end of; the armature lever does not disturb L", but the armature lever pushes the sprin, L away from the support of'the contact L1 with the result that the.

is ofthe kind used forreleasing the switches,

at the local stations, the weighted armis thrown to its alternate position with the re suit that the electrical connection between L and L. is broken and not reestablished until another stepping impulse is sent through the magnet L As the circuit for the lamp includes the connection between L and L, the lamp is extinguishedby this action. v

The operation will be explained by assumingthat asubscriber at one ofthe stations on a party line has sent in a signal to operate the drop for that line, and that the operator has inserted the plug in the jack,- has answered in the ordinary way, and has learne d that the-calling subscriber i'sat station No. 1 and wishes to talkto the subscriber at station No. 12 on the same line. The operator being thus informed ofwhat stations are to be connectedv toeach other in a talking circuit shepresses keys V marked It is to be noted in this connection that the contact springs associated with these keys are shown atthe left of the diagram, but that this diagram shows only springs forpart of-these' keys, it being understood that the springs for the additional keys are to be connected in series in the same way as those shown. In other words, the diagram shows connections complete for eight stations on one party line, while Figs. 7 and 8 show a device capable of use on party lines having eighteen stations. hen the operator depressed keys 1 and l2 the circuit was made for magnet B upon depression of the first one with the result that both were held in depressed condition by said magnet. The circuit for the magnet B also includes the switching relay C in series with B and is as follows :-battery VV15-16B1718-192021 is completed instantly-upon pressing one of the station keys V, and the consequent energization of the switching relay C cuts off the generator Gr at the contact so that when the operator immediately after pressing the station keys pushes the ringing key K to the right, it is the calling mechanism and not the generator which is connected to the line.

Pressing the key K closes a circuit as Upon the cessation of followsz-main battery X27-28.29:-- ground: at central to ground at all of the local stations on the line and then in multiple through the stepping magnets L to the tip side of the line (also signal magnet 3(i37-.3839 -i0llD-l2-X.

The magnet D is called the starting relay and is preferably sensitive. The impulseflowin over the circuit 'ust described is in H the release direction for the stepping mag nets L at the local stations and consequently serves to bring. the apparatus at the stations to normal position in case they were oiinormal when this impulse was sent. Energiz- 111g the starting relay D closes a circuit as Also a parallel branch for itself as fol lows: Y4344-5253515556-,.

The closing oi the clutch M and. the

starting of the motor Mi-starts the wheel P into motion to cause the serrations to pass over the-pin P to vibrate the contact spring 36, remove the pin P from the adjacent reversing springs, and: to move the contact makers R and S over their contact pins R and S The first notch P reached the pin P at the same time that the pin P permits the reversing springs to change position. The shifting of the reversing springs breaks the circuit through the starting relay D and also through the stepping magnets L at the local stations. As the clutch magnet A closed circuit for itself, the shifting of the reversmg springs did not afiect that magnet.

The movement of the serrations 1 over the pin P vibrates the spring 36 between contact points above and below. When 36 strikes the contact below a current flows as follows :battery X-275 7-393S-37- 3635 3433--323130tip side of the line to all stations thereon-magnets L ground-29-58 59X. It will be seen that this starts from the same side of the batteryas before but that it goes over the line and through the stepping magnets L in the opposite direction from that previously given. This impulse is a stepping impulse and advances the ratchet wheels of all stations one step. It also operates the magnet L at the central ofiice to close a circuit for the lamp L and thus to indicate to the operator that the stepping impulses have begun.

hen the spring 36 rises this circuit is broken and another circuit over the same course is completed to the small battery Z. This battery has its poles so related to the contact spring 36 that the impulse from said battery is in a direction opposite to the stepping impulses. This impulse, however, does not release the switches at the local stations for the reason that the battery is made too small and weak to eiiect this result. The object of this light impulse in the reverse or release direction is to kill the residual magnetism in the magnets L and thus prevent their armatures from sticking. As the wheel I" advances these stepping impulses continue to ad rance the ratchet wheels at the local stations. Also, each stepping impulse temporarily breaks the circuit tor the signal lamp L exhibits a series of successive flashes which indicate to the operator that the stepping impulses are going over the line. If she chooses to count these flashes she can do so and thus know how many stepping im pulses are being sent. If for any reason these flashes do not appear she can know that somcthin is wrong and have steps taken to remedy the defect. The flashes of light from the lamp L, therefore, indicate that the apparatus is working properly.

\Vhile the contact spring 36 is vibrating as described the contact makers 1t and S are traveling over their respective contact pins. \Vhen the contact maker B strikes a in R connected to a spring contact closed by a depressed key V, a current flows from the ringing machine or generator G as follows :-Gr6()-spring 61 of the highest numbered key in the row of keys in which the depressed key is located, and then on through other springs 61 until the one is reached which was moved by the depressed key V62-68-touched contact pin R 6566-67-sleeve side of the line to the local station which corresponds to the key V which was depressed68 which is connected to the sleeve side of the line at each stepping movement of the magnet L- cut-in coil Q.groundG.

Immediately after the last mentioned impulse is sent the contact maker S engages the pin S which corresponds to the key depressed. If only one key had been depressed then a current would flow as follows :-\V 156869-70and on through other con tacts 69 and 70 until the contact 69 is reached which has been moved by the depressed key V-7l72touched SS- 64E-7 326-V.

The original assumption, however, was that keys 1 and 12 had been depressed for stations No. l and No. 12. Under these conditions this circuit will not be completed for key 1 because the contacts 69 and 70 for key 12 are not in engagement with each other, but will he completed when S strikes the pin S connected to the contact 71 for depressed key 12. In the meantime, however, stepping impulses go 011 until contact R engages the pin R connected to spring associated with depressed key 12" when the cut-in coil Q, of station No. 12 will be operated the same as previously described for station No. 1. Then will follow the circuit last described passing through the spring 71 which belongs to depressed key 12. The circuit described through the release relay E causes that relay to break the connections between 23 and 24. As these contacts are in the before mentioned circuit for the magnets B and C, the break at 2324 breaks the circuit for these magnets. Breaking the circuit for B permits the depressed keys V and their associated springs to return to normal position. Breaking the circuit for G permits the associated springs to return to their normal position which is that shown in the diagram. This last action cuts off the calling device and throws the ringing machine on the line as follows :--G7 5-7667 sleeve side of the line to stations No. 1 and No. l277receiver hook-ringer-contacts closed by Q-tip side of line-303l-32 337879-80-81-82G-. This signals selected stations.

Breaking the circuit through C also breaks the circuit for the clutch magnetA at 5253, and the release of the clutch magnet in turn breaks the circuit for the motor M at 5051. As a consequence the advance of the Wheel P is stopped the instant the contact maker S strikes the pin S which corresponds to the highest numbered key V which had been depressed. The point to which it is desired to here call attention is that by building-up the connections between the springs con trolled by the keys V, the impulse sending device is automatically stopped the instant it has sent impulses enough to reach the highest numbered key depressed irrespective of What that number may be. Heretofore it has been the practice to send out over the line as many impulses as there were stations on the most heavily loaded party line served by the impulse sender. Thus, if a line should have twenty stations on it and station No. 1 should be'the onlystation wanted, still twenty stepping impulses would be sent. In the present arrangement, if station No. l is the only one wanted, then immediately upon completion of one stepping impulse and one cut-in impulse, the apparatus will stop and return to normal position.

It has been hereinbefore stated that the operator holds the ringing key pressed to the right during the impulse sending, and that she can observe the impulse sending by the flashing of the light L l/Vhen the impulse sending device is cut oil' and the ringing machine G thrown on the line by breaking the circuit through the switching relay C, the flashing of the light L ceases and the operator knows that all required stepping impulses have been sent and that the ringers of the selected stations are connected to the line. To insure the proper ringing she ammo o ds e ke K i017 af s c n s er he flashing of the, light L ceases. then releases it. The calling apparatus may then be used onsomeother party j p K I When the subscr bers havefinished talking the operator is notified throilgh an ordinary clearing out drop connected in the cord circuit, which drop; isnot. shown as it may be of the ordinary kind and has no dn'ect bearing upon the present invention. When; the operator is so signaled she presses the key which is marked! R and also; again presses the key A circuit then completed follows:- X27 -28 29 ground-all local stations on, the line-L tip side of the line31Q 31, 32 ,--33-78+ ve -somsswse- Xr The impulse w i flows fromthe battery X over this courseis in the release direction and restores the apparatus of the local stations to normal position, A branch also goes; through the, magnet L and extinguishes the light L. ,The particular key V which is marked R to represent release, does. not close a circuit fo the agnet B, as it, opens that r uitat 17-48, and consequently it is not automatically held down when depressed. The key R is also used to restore the central otfice apparatus to normal position before stepping impulses are; sent overthe line in case the operator discoversthat she has inadvertentlypressed keys V for wrong numbers. This last is; by reason of thefact; that it? opens the circuit tor the magnet B at 1 #18.

What I claim is: p v

1. The combination with a party line-,of an impulse sending device, keys for indicating different stations on the party line, means for connecting the impulse sending device to the line and starting the same into operation so that impulses, there-from will flow over the line, and automatically operating means for stopping the impulse sending device as soon as the impulses sent over the line are 'suflicien t in number to telephonically connect to. the line, the station previously indicated by a depressed key.

2. The combination with an impulsesend ingdevice; keys 01? indicating difierent numbers, of impulses, to be. sent, and means for holding two or more; keys representing difit'e'rent numbers simultaneously in a depressed position, of means for starting the impulse sending device into operation, means by which devices associated with the depressed key having the highest number will automatically operate to stop the sending of impulses, and meansby whiehu ev ices associated with all other keys will be, inefteetive o p he sen ixhn o impuls s The combinati n with an l pfilsesending device, and keys for ind-icatingdifierent numbers of. impu ses. a p ai aliztyof which may be simultaneouslyn a depr prmsn pulatedi positio i m ans fi 'zfiiial le the. impul e sen ing; device i t opera.- t10n,,a;nd means for automatically-stopping the. n g f. pulses wh n thenumber sen-t corresponds to the hinhest number e ted y he di r nt m nipulate ys 4c. 'Ihe combination with an impullse send?- ln-g device, and means for operating it of a series of keys each of which, indicates a diff fierentnumber ofimpulses desired from said device, means by which a plurality of said keys may be simultaneously in indicating posit on, and means-by. which said device is automatically stopped when the number of impulses supplied corresponds to, the munber alled for W he-highe t num r key that as at the time in its, indicating p0 sitmn,

; 5-' I a calli g epn r t aa r es fkea for indicating ditterent stations on a party ne, a magnet t r holding moved keys i their movedppsition, meansby which a cirsuit is completed for said mag-netupon the movement of any one of said keys, an innpulse sending device havingmits, impulse sending operations. controlled by a moved key, and means by which the stopping of said device breaks the circuit for said magnet,

n a a l ng appar us, a s ries f k ys,

' contactsprings tor each key operated'bythe manipulation of their respectivekeys,, co npe i i ns f omth-e p ings; t di feren keys to a corresponding series of terminalga'contact, maker adapted to be moved over said te ls, a mot r f r S0 mo n i an automatically operating means for stopping said motor when said contact maker engages a terminal corresponding to the operated springs of amanipulated key. Y

7 In a calling apparatus, a series of keys, contact springs for each key, a corresponding series ct contact pins, connections from the different springs to corresponding pins, a contact maker adaptedpto be moved: over said pins, a motor for so moving itand means for automatically stopping said motor when said contaot maker engaies. aipin; eonnected to a spring moved by a h ta In a calling apparatus, "a series of numer key v plura y ich may simuiL taneonsly be m 2, moved p sition, a c rresponding series of contact springs operated by the movement of their resptectivekeyaa corresponding series of contact points each of. Whie is e n sct dt a p r icu ar one of said springs-pa contact maker-adapted to eng ge the poi s ss n, e mo or tor m ving sa d c nat maker so as o aus su h eng gement; nd eans t r automatia y st eping said mo or when said con ent maker engages the oint eorresponding to the, highest numbere key in a moved position v ing a serie 'ef stations t ereon ach of which is provided with a steppin magnet and" a cut-in magnet, of a device a apted to send enough impulses over the line to cause the operation of any one or all of the cut-in magnets, a series of keys numbered to represent the different stations on the line, means by which one oi more keys moved from normal position'serve to indicate desired stations and .to control the impulses flowing over the line so as to cause the operation of the desired ones of the cut-in magnets, and automatically operating means for cutting ofl impulses from the line as soon-as enough are sent to operate the cut-in magnets of indicated stations.

10. The combination with a party line and a device for sending impulses thereover, of a series of numbered keys, the numbers of which represent a definite number of impulses it is desired shall be sent over the line, and means associated with said device and manipulated keys for automatically stopping impulses over the line when the number sent corresponds to the number called for by such manipulated keys.

11. A series of numbered keys for indicating difl'erent stations on a party line, of a magnet for holding. moved keys in their moved position, means by which a circuit is completed for said magnet upon the movement of any one of said keys from its normal position, an impulse sending device controlled by said keys and means by which the circu1t for said magnet is broken when the impulses sent by said device are of the number required to select the station represented by the highest numbered key which is at the time in its moved position.

12. A series of numbered keys representing correspondingly numbered stations on a party line, a party line and a device for sending im ulses over such line, means by which the impulses sent are controlled by the keys moved from normal position, and 15 controlled by the impulse sending device.

means by which the return of moved keys is 13. The combination with a party line, an impulse sending device, and means for connecting said device to and separating it from said party line, of automatically operating means for separating said device and line at any predetermined point in the normal operation of said device.

7 14. The combination with an impulse sending device, and a motor for operating it, of a relay fors'tarting the device into operation, a circuit for said rela a party line circuit, and means control ed by the movement of said device for breaking the circuit of the relay and for connecting the party line circuit to the device.

15. The combination with an impulse sending device, and a relay for starting it into operation, of a arty line over which a d for said relay, and

means controlled by the operatiori of said device for disconnecting said relay from and connecting the device to the party line.

16. The combination with a party 'l1ne, an impulse sending device, a relay for startlng it into operation, and a generator for sending signaling impulses over the line, of a series of keys for indicating different stations on the line, devices for holding moved keys in moved position, means by which the trolled by the operation of said device for shifting the party line connection from the relay to the device and for releasing the moved key as soon as the desired number of impulses have been sent over the line, and means controlled by the release of the key 1for again connecting the generator to the 17 The combination with a party line, a series of keys for indicating stations on the line, devices for holding moved keys in moved position, an impulse sending device, and a relay for starting the device into operation, of means for operating said relay over the line, means controlled by the operation of the device for shifting the line connection from the relay'to the device and for releasing previously moved keys, and means controlled by the release of the keys for again disconnecting the device'from the line.

18. The combination with a party line, and an impulse sending device, of a series of keys for indicating diflerent stations on the line and for controlling the number of impulses sent over the line by said device, de vices for holding moved keys in moved position, and a special key R for restoring previously moved keys to normal position.

19. The combination with a party line, wiching mechanism at each station thereon, and a device for sending impulses for operating such mechanisms, of a series of selecting keys for controlling said device so as to produce desired movements of the mechanisms, devices for holding moved keys in moved position, a special key R for restoring the moved mechanisms to normal position, and means by which said special key may also be used to restore inadvertently moved selecting keys to normal position.

20. The combination with a party line, of

a series of keys indicating different stations on the party line, a signaling circuit, an impulse sending device and a circuit therefor,

when the impulse sending device hasreached 1 impulse sending device to thepartv line, of

pressed key.

' 21. The combination with an impulse, sending device, a series of numbered keys, a

party line, and a relay for connecting the means whereby the operation of a key controls the relay to make such connection, and means by which such connection is maintained until the impulse sending device has ieached a position indicted by the moved 22. The combination with a party line, a magnet at each local station on the linefor advancing and releasing mechanism thereat, 1

and apparatus for sending appropriate impulses over said line and through the magnets at the stations, of a supervisory light for the party line, and a magnet for controlling said light, said last named magnet being operated by the impulses sent by said apparatus and in consonance with the'magnets. at the local stations.

Signed at Chicago, 111., this 18th day of March, 1911.

CLARENCE A. ANDERSON.

Witnesses:

WALTER H. REDFIELD, JAMES D. LYNCH,

copies of this patent may be obtained for five cents each, by addressing thefcommi ssioner of Patentl.

.Washington, D. G. 

